In a production process for semiconductor devices such as IC, LSI or the like, lithography technology is applied to the formation of wiring and to the formation of via holes in an insulating interlayer. Briefly, a resist is uniformly applied onto a conductive metal film of Al, cupper (Cu), Al alloy or the like or an insulating film of silicon oxide (SiOx) film or the like formed on a substrate, and patterned through photoexposure and development, and via the resist serving as a mask, the conductive metal film or the insulating film is dry-etched and then the unnecessary resist and the resist residue denatured through dry etching are removed to attain wiring formation or via hole formation in the insulating interlayer. After dry etching, often employed is a method of removing the unnecessary resist by plasma etching. Around the pattern thus formed by such dry etching followed by ashing, there remains a resist residue (protective deposition film) or a metal residue derived from a plasma gas-denatured interlayer insulating material or wiring material (hereinafter these may be collectively referred to as residues).
When such residues remain, they may be a cause of disconnection and may bring about various troubles, and therefore, it is desired to completely remove them. For removing the remaining residues, there is employed cleaning treatment with a cleaning agent (residue removing liquid composition).
In dry etching and ashing for via hole formation in a production process for a semiconductor substrate having Al alloy wiring with a titanium (Ti)-based alloy serving as a barrier metal, the resist residue is a residue derived from the resist that remains on the surface of the substrate after dry etching and ashing, and the metal residue derived from the wiring material denatured by plasma gas is an oxidation product of a metal component, Al, Cu or Ti, especially Ti among them remaining on the side wall and the bottom of a via hole (hereinafter referred to as titanium (Ti)-derived residue).
Heretofore, for completely removing the resist residue or the Ti-derived residue, used is a chemical liquid, and for example, there is proposed a residue removing liquid composition comprising “a mixed liquid of an alkanolamine and a water-soluble organic solvent” (for example, see Patent References 1 and 2). The removing liquid can function only at a high temperature taking a long time, and is therefore used in a batch cleaning apparatus. Recently, however, for efficiently cleaning a large variety of devices, the cleaning method is being changed from a batch mode method to a sheet-fed mode method suitable for manufacturing of a wide variety of products in small quantities. The sheet-fed mode cleaning apparatus requires low-temperature short-time treatment, in which, therefore, the above-mentioned organic amine-based removing liquid could not be used. Accordingly, in sheet-fed cleaning treatment, the resist residue and the Ti-derived residue must be removed at a low temperature in a short time.
As a residue removing liquid composition applicable to low-temperature short-time treatment, a lot of patent applications have heretofore been filed relating to a fluorine compound-containing liquid. For example, as a residue removing liquid composition having the advantage of usability of pure water as a rinsing liquid, there is proposed “a composition comprising a fluorine compound, a water-soluble organic solvent and an anticorrosive” (for example, see Patent References 3 and 4). Recently, however, a large quantity of Ti-derived residues have become formed along with advanced micropatterning in wiring, and the composition containing a fluorine compound and a water-soluble organic solvent could not remove resist residues or Ti-derived residues. In addition, the composition containing a fluorine compound and a water-soluble organic solvent has the property that, when diluted with water, its etching rate to Al alloy increases; and in case where substitution of the chemical liquid with water could not be attained rapidly for some reasons in the process of chemical liquid treatment-rinsing with pure water, the liquid diluted with water to be more corrosive to Al alloy may be kept in contact with the substrate to corrode the Al alloy wiring part. This is another drawback of the composition.
For enhancing the resist residue and Ti-derived residue removability, there has been created a method of adding an acidic additive to the fluorine compound-containing composition. Patent Reference 5 proposes “a fluorine compound-containing liquid comprising a fluorine compound and a sulfonic acid”; however, the chemical liquid could not exhibit sufficient anticorrosive performance for interlayer insulating films and via hole bottoms (see Comparative Example 34).
Patent Reference 6 proposes “an acidic aqueous solution containing an organic phosphonic acid and a fluorine compound”; however, the chemical liquid could not sufficiently remove residues and could not exhibit sufficient anticorrosive performance for via hole bottoms (see Comparative Example 35).
Patent Reference 7 proposes “a fluorine compound and orthoboric acid or orthophosphoric acid and a water-soluble organic solvent”; however, the chemical liquid could not sufficiently remove residues (see Comparative Example 36).
A water-soluble organic solvent is often added for anticorrosion to the composition prepared by adding an acidic compound to the fluorine compound-containing composition; however, the resulting composition has a drawback in that, like the composition containing a fluorine compound and a water-soluble organic solvent, its etching rate to Al alloy increases when diluted with water and, as a result, the composition corrodes the Al alloy wiring part.
Patent Reference 8 proposes “a semiconductor substrate cleaning liquid containing acetylene alcohol for removing metal contamination and containing a fluorine compound and a water-soluble or water-miscible organic solvent”; however, this has no description relating to the effect of the added acetylene alcohol for anticorrosion to metal wiring.
Patent Reference 9 proposes “a cleaning agent for semiconductor device production, which comprises an aqueous solution containing acetylene alcohol for increasing the deposited polymer removing speed, and containing a fluorine compound, boric acid and a water-soluble organic solvent”; and Patent Reference 10 proposes “a cleaning liquid for semiconductor device production, which comprises an aqueous solution containing acetylene alcohol for increasing the deposited polymer removing speed, and containing an organic carboxylic acid ammonium salt and/or an organic carboxylic acid amine salt, a fluorine compound, a water-soluble or water-miscible organic solvent, and an inorganic acid and/or an organic acid”. However, these have no description relating to the effect of the added acetylene alcohol for anticorrosion to metal wiring.
Patent Reference 11 proposes “a composition containing at least one of an acetylene alcohol compound and an organic sulfonic acid compound, and at least one of a polyalcohol and its derivative, and further containing at least one of a fluorine compound and a quaternary ammonium hydroxide salt”, in which, however, the composition is proposed for production of semiconductor circuit devices having metal wiring of mainly Cu as the wiring material. However, in Patent Reference 11, the samples were evaluated in point of wiring with tantalum as a barrier metal, and there is given no description relating to Ti-derived residues. In this, in addition, there is also given no description relating to a chemical liquid containing both a fluorine compound and an organic sulfonic acid. In addition, the residue removability of the chemical liquid was not sufficient (see Comparative Examples 37 to 39).
In addition, patent application have been filed relating to a residue removing liquid composition that comprises a fluorine compound-containing liquid and an additive added thereto. However, a residue removing liquid composition having corrosion resistance to interlayer insulating film materials, wiring materials and others and having good removability of resist residues and Ti-derived residues is not as yet developed, and it is desired to develop such a residue removing liquid composition.    [Patent Reference 1] JP-A 62-49355    [Patent Reference 2] JP-A 64-42653    [Patent Reference 3] JP-A 7-201794    [Patent Reference 4] JP-A 8-202052    [Patent Reference 5] JP-A 2006-66533    [Patent Reference 6] JP-A 2006-191002    [Patent Reference 7] JP-A 11-67703    [Patent Reference 8] JP-A 2000-208467    [Patent Reference 9] JP-A 11-323394    [Patent Reference 10] JP-A 10-55993    [Patent Reference 11] JP-A 2006-251491